Effect of soaking process on nutritional quality and protein solubility of some legume seeds

Legume seeds (soy bean, lupin and bean seeds) were soaked in 0.5% sodium bicarbonate in attempt to evaluate their nutritional quality and protein solubility index. Soaking process led to an increase in the hydration coefficient, seed weight, total protein, ash, fat, fiber, while non protein nitrogen, total carbohydrates, starch, stachyose, raffinose, reducing sugars, and minerals (except Na) were decreased. All antinutritional factors such as phytic acid, tannin, trypsin inhibitor and hemagglutinin activity were decreased during soaking in 0.5% sodium bicarbonate; it was the same for the protein solubility in different solutions, while the in-vitro protein digestibility and available lysine were increased.